Sesame Allergy Underrecognized in U.S.

Sesame seed allergy is far more common in the U.S. than previously recognized in both children and adults, but the food allergy remains largely undiagnosed, researchers report.

Their cross-sectional analysis, based on a survey of more than 50,000 households, suggests that as many as 1.5 million children and adults in the U.S. have sesame allergies that can be severe and even life threatening.

In the survey sample, 0.49% had a current sesame allergy and 0.23% met the criteria for convincing IgE-mediated allergy.

One in three children and adults with sesame allergy had severe allergic reaction symptoms, and one in three also reported treating such reactions with an epinephrine autoinjector at some point in the past, reported Ruchi S. Gupta, MD, of the Center for Food Allergy and Asthma Research at Northwestern University Feinberg School of Medicine in Chicago, and colleagues.

The study findings, published in JAMA Network Open, "demonstrate a substantial and likely growing burden of sesame allergy in the United States," the team wrote.

The findings may also have important implications for health policy with regard to food labeling, Gupta told MedPage Today.

The FDA is currently considering adding sesame seeds to the current list of allergenic foods that must be labeled on food packaging, which now includes peanuts, milk, shellfish, tree nuts, eggs, soy, fin fish, and wheat.

The current study was conducted in response to the FDA's request for additional information on the prevalence and severity of sesame allergy in the U.S. "There is a push to add sesame to the list, because it is so often a hidden ingredient in processed foods," Gupta said.

She noted that such labeling is already required in Canada, the European Union, and Israel. "Now that we know that sesame allergy is also quite prevalent in the U.S., it's time we included it as well," she said.

Writing in an accompanying commentary, Jennifer Protudjer, PhD, and Elissa Abrams, MD, both of the Yee Centre for Healthcare Innovation at the University of Manitoba in Winnipeg, said that that while the analysis "provides support for consideration of listing sesame as a top allergen in the United States," questions remain.

Protudjer and Abrams noted that 81.6% of the survey respondents reporting sesame allergies also noted having other food allergies, with almost half of them peanut allergies.

"This demands a need for multiple testing in individuals with suspected sesame allergy who also present with possible peanut allergy and points to a need for ongoing studies to further delineate the natural history of sesame allergy," the commentators wrote. "To our knowledge, there is no known cross-reactivity between the major allergenic proteins in sesame and peanut. Further investigation into sesame and peanut components may be warranted."

Study Details

The cross-sectional study included data from a detailed food allergy prevalence survey administered to a nationally representative sample of U.S. homes from fall 2015 to fall 2016. A total of 51,819 households were included in the analysis, with food allergy information obtained from about 40,443 adults and 38,408 children.

The researchers made the following estimates, based on the survey responses:

• About 0.11% (95% CI 0.08%-0.16%) of respondents "had a sesame allergy reported as physician diagnosed but did not report reactions fulfilling survey-specified convincing reaction symptoms"

• Of those with established IgE-mediated sesame allergy, an estimated 23.6% (95% CI 16.9%-32.0%) to 37.2% (95% CI 29.2%-45.9%) had experienced a prior severe sesame-allergic reaction

• A total of 81.6% of participants (95% CI 71.0%-88.9%) had at least one additional food allergy and 33.7% reported prior epinephrine use for reactions to sesame ingestion

The study's first author, Christopher Warren, PhD, also of Northwestern University Feinberg School of Medicine, told MedPage Today that sesame allergy has previously not been recognized as a food allergy that affects adults as well as children: "What our data show, and this is consistent with other countries, is that the rates are just as high in adults," he said.

In addition, he noted, about 25% of adults who are allergic to sesame developed their allergic reaction during adulthood.